It has been the custom in tandem seat motorcycles to provide a commercially available sissy bar, to support the back of the passenger in the rear seat of a tandem seat and to rely on the passenger to support the back of the driver. There are also available combined back rests and carriers for the passenger in the rear seat, both the sissy bars and the back rest carriers usually comprising an inverted U-shaped member having an upstanding, rearwardly inclined back pad portion and a lower forwardly bent portion for attachment to the motorcycle.
It has been found that permanently mounting such back rests at the rear of the rearward seat is no help to a solo driver, having no passenger, on a trip of several hundred miles, the lack of back support often causing considerable pain and extensive tiring.
It has been proposed in U.S. Pat. No. 3,549,172 to McBroom of Dec. 22, 1970 to provide three hinged pads, one forming a driver's seat pad, the next forming either a passenger seat pad or a back rest pad for the driver and the third forming a back rest pad for the passenger. However, this device does not make use of the existing tandem seats on motorcycles, but substitutes new seats instead.
In U.S. Pat. No. 3,913,974 to Bowen of Oct. 21, 1975 a portion of the seat of the rear passenger pivots upwardly to form a back rest for the front seat, but as in the McBroom patent above, a special seat would be required rather than using the original equipment tandem seat.